What I should do with 120K?

[Carla Quiroga]

My parents are both over 65 years old and have saved nearly 120K in cash. While my dad loves the idea of investing his money in something like a bond or IRA, given his age, I'm not sure that's the best option. They are currently renting a 2bdrm apartment for 1300/month, which I realize is great for LA, but, unnecessary now that my brother and I no longer live with them. They've not moved out of the apartment because finding that price point is nearly impossible in this area. I would really like for them to start positioning themselves to be comfortable and retire. My husband and I recently purchased a home and I've suggested using their money to convert our garage into an ADU.

My question is how you all might consider investing/using 120K given the situation I described above? What options or combination of options I might not be aware of? 

While I don't believe either of my parents will ever stop working, my ultimate goal is to relieve them of the stress of HAVING to work.